1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, a flexible liquid crystal display device and a method of manufacturing the same.
2. Discussion of the Related Art
Until recently, display devices have typically used cathode-ray tubes (CRTs). Presently, many efforts and studies are being made to develop various types of flat panel displays, such as liquid crystal display (LCD) devices, plasma display panels (PDPs), field emission displays, and electro-luminescence displays (ELDs), as a substitute for CRTs. Of these flat panel displays, LCD devices have many advantages, such as high resolution, light weight, thin profile, compact size, and low voltage power supply requirements.
In general, an LCD device includes two substrates that are spaced apart and face each other with a liquid crystal material interposed between the two substrates. The two substrates include electrodes that face each other such that a voltage applied between the electrodes induces an electric field across the liquid crystal material. Alignment of the liquid crystal molecules in the liquid crystal material changes in accordance with the intensity of the induced electric field into the direction of the induced electric field, thereby changing the light transmissivity of the LCD device. Thus, the LCD device displays images by varying the intensity of the induced electric field.
FIG. 1 is a perspective view illustrating an LCD device.
Referring to FIG. 1, the LCD device 10 includes a liquid crystal panel including an array substrate, a color filter substrate and a liquid crystal layer 50 between the array substrate and the color filter substrate, and a backlight unit supplying a backlight to the liquid crystal panel.
The array substrate includes gate and data lines 26 and 22 crossing each other on a first substrate 21 to define a pixel region P. In the pixel region P, a thin film transistor T is connected to the gate and data lines 26 and 22, and a pixel electrode 28 is connected to the thin film transistor T.
The color filter substrate includes a black matrix 32 on a second substrate 31, and red (R), green (G) and blue (B) color filter patterns 34a, 34b and 34c in the respective pixel regions P. A common electrode 36 is on the black matrix 32 and the color filter patterns 34a to 34c. 
The gate lines 26 are sequentially selected and supplied with an on gate voltage, the thin film transistor T is thus turned on, and a data voltage is supplied to the pixel electrode 28. Accordingly, an electric field is induced between the pixel electrode 28 and the common electrode 36, and alignment of the liquid crystal molecules of the liquid crystal layer 50 changes in accordance with the intensity of the induced electric field.
The first and second substrates 21 and 31 are made of glass. Recently, portable terminals such as PDA (personal digital assistant) have been widely used, and a flexible LCD device using flexible substrates is thus proposed since the flexible substrate has advantages such as low weight and flexibility. However, it is difficult to apply the flexible substrates to conventional apparatuses for quartz or glass substrates. For example, the flexible substrates are not transferred by a track device or robot, or not placed in a cassette.
To resolve these problems, proposed is a method that, in a state that the flexible substrate is attached to a base substrate of quartz or glass, manufacturing processes are performed for the flexible substrate, and then, at a predetermined time, the flexible substrate is detached from the base substrate. However, this method increases the production cost since the cost of glass and quartz increases. Further, it is difficult to detach the flexible substrate from the base substrate since a temporary adhesive is attached to an entire surface of the base substrate, and some of the temporary adhesive may remain on the flexible substrate even after detaching the flexible substrate from the base substrate. Accordingly, an additional cleaning process is required to remove the residual temporary adhesive on the flexible substrate.
Further, the temporary adhesive should have an appropriate adhesive strength capable of preventing the flexible substrate from being detached from the base substrate in the manufacturing processes, and of easily detaching the flexible substrate from the base substrate after the manufacturing processes. However, it is difficult to select the temporary adhesive having such the appropriate property. Further, the cost of the temporary adhesive is high, and production cost of the LCD device thus increases.